Hello, this issue caused by isl95859c ic, replaced ic but i have black screen, VCC and VIN was shorted on that ic. I have voltage on vcc and vin after replace but missing VR_EN signal, there is no short for cpu. What should i check now? Can it be bad isl95859c chip again?
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Re: Dell inspiron 13 7386 BLACK SCREEN
VR_EN is enabled only after POWER GOOD signal is OK to indicate that all power rails are stable.
See attached.
Check the POWER GOOD voltage for the linked parts.
Post your values.
The schematic shows that there is a single gate open drain buffer for VR_EN but unable to find this part in the schematic in my database. Guessing that the engineers did a cost reduction and used the diodes and pull-up resistors to emulate the same function.Attached Files -
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Re: Dell inspiron 13 7386 BLACK SCREEN
Checked with boardviewAttached FilesComment
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Re: Dell inspiron 13 7386 BLACK SCREEN
VR_EN has 3.36, VR_RDY missingComment
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Re: Dell inspiron 13 7386 BLACK SCREEN
What is the voltage of VR_RDY ?Comment
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Re: Dell inspiron 13 7386 BLACK SCREEN
Confirm the voltage on both pins of PR4609.Attached FilesComment
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